I don't have a lot of people I think of as really close friends in the first place; not in the sense of bosom buddies that are with me in everything. Part of it is that I've moved around a lot; not many people I grew up with or went to school with are around, most of the people I am around haven't known me too long, don't have a lot of history with me. The other is the variety of my interests and areas of life; I'm a churchgoing guy, a bar/garage band musician, and an academic, and there isn't a whole lot of overlap between those three worlds, at least not where I am. So in any given circle I'm involved in, a lot of my life is "outside" that circle, too much for people in that circle to really have that kind of "wingman" closeness. The idea of a social "floater" that people use to describe high school social dynamics still kind of applies to me - the person who moves between different "tribes" and is accepted in them but doesn't really belong to any particular one.
Honestly it makes me uncomfortable when people I just barely joined up with start calling me "brother" and acting like I'm family. It seems superficial. I appreciate the warmth, but they don't really understand that much about me.
With that having been said, yes, to a degree, I think of bandmates as friends. It's a sliding scale, and some more than others. My singer friend Carolyn, for instance, I've been in a couple of bands with, none at the moment, and would definitely consider her a friend. Likewise my drummer Vance, whom I've known for less of a time but worked with more intensively and gotten to know his family. Others are more arm's-length friendly acquaintances.